I will say that I have gotten eggs that had many broken eggs and had to toss the rest as the egg contents all over them really makes them unusable IMO. Sounds like that was the case so I would send the same amount and not just "a few", cost to ship is the same
replace at no charge, I wouldn't have the buyer pay shipping as they weren't packaged properly..... well, sounds like they would have been fine up until the choice of box